固沙灌木配置模式对宁夏东部风沙区土壤生态化学计量特征的影响

Effects of sand-fixing shrub patterns on soil ecologi⁃ cal stoichiometric characteristics in eolian sand re⁃ gion of eastern Ningxia,China

摘要:

为探讨宁夏东部风沙区不同固沙灌木配置模式对土壤养分含量及其生态化学计量比的影响，以宁夏灵武白芨滩国家级自然保护区典型固沙灌木样地为研究对象，分析 5 种固沙灌木配置模式 (柠条纯林、杨柴纯林、柠条×花棒混交、柠条×沙拐枣混交、花棒×沙拐枣混交)下土壤碳、氮、磷含量及其生态化学计量比。结果表明：0~10 cm 土层，柠条×花棒混交、柠条×沙拐枣混交固沙灌木配置模式的土壤全氮含量和 N∶P 均显著高于其他 3 种固沙灌木配置模式，但土壤 C∶N 显著低于其他 3 种； 10~20 cm 土层，柠条纯林、柠条×沙拐枣混交固沙灌木配置模式土壤 C∶N 显著高于其他 3 种，柠条纯林固沙灌木配置模式土壤 C∶P 显著高于其他 4 种；20~30 cm 土层，柠条纯林固沙灌木配置模式土壤全氮含量显著高于其他 4 种，柠条×沙拐枣混交固沙灌木配置模式土壤有机碳含量和 C∶P 均显著低于其他 4 种。C∶N 和 N∶P 主要限制因素均为全氮，C∶P 主要限制因素为有机碳。柠条×花棒混交、柠条× 沙拐枣混交固沙灌木配置模式有利于表层土壤氮矿化，提高土壤全氮含量，促进沙地土壤养分的平衡。

Abstract:

In order to investigate the effects of different sand-fixing shrub allocation patterns on soil nutrient con- tent and ecological stoichiometric ratio in the aeolian sandy area of eastern Ningxia， a typical sand-fixing shrub plot in Lingwu Baijitan National Nature Reserve of Ningxia was selected as the research object. The effects of five sand-fix- ing shrub configurations (pure shrubland of Caragana korshinskii， pure shrub land of Corethrodendron fruticosum var. mongolicum， mixed shrub land of C. korshinskii and Corethrodendron scoparium，mixed shrubland of C. korshin- skii and Calligonummongolicum， mixed shrub land of C. scoparium and C. mongolicum) on soil carbon，nitrogen and phosphorus content and their ecological stoichiometry ratio were analyzed. The results showed that in the 0~10 cm soil layer， soil total nitrogen content and the N∶P ratio of the mixed shrubland of C. korshinskii and C. scoparium， and those of the mixed shrubland of C. korshinskii and C. mongolicum were significantly higher than those of the other three sand-fixing shrub configuration patterns. But the soil C∶N ratio of the mixed shrub land of C. korshinskii and C. scoparium， and that of the mixed shrub land of C. korshinskii and C . mongolicum were both significantly lower than that of the other three patterns. In the 10~20 cm soil layer， the C∶N of the shrub land of C. korshinskii， and that of the mixed shrub land of C. korshinskii and C. mongolicum were both significantly higher than that of the other three patterns， and the soil C∶P ratio of the shrubland of C. korshinskii was significantly higher than that of the other four patterns. In the 20~30 cm soil layer， the soil total nitrogen content of the shrub land of C. korshinskii was signifi- cantly higher than that of the other four patterns，and the soil organic carbon content and the soil C∶P ratio of the mixed shrub land of C. korshinskii and C. mmongolicum were both significantly lower than those of the other four pat- terns. The main limiting factor of C∶N ratio and N∶P ratio was the total nitrogen content，while the main limiting fac- tor of C∶P ratio was organic carbon content. The mixed shrubland of C. korshinskii and C. scoparium， and the mixed shrubland of C. korshinskii and C. mongolicum were beneficial for surface soil nitrogen mineralization and the increase of soil total nitrogen content，and were also beneficial for promoting the balance of soil nutrients in sandy areas.